Making gutta-percha boats



UNITED STATES PATENT OFFICE.

EDWIN B. LARCHAR, OF BALTIMORE, MARYLAND.

MAKING GUTTA-PERCHA BOATS.

Specification of Letters Patent No. 13,315, dated July 24, 1855.

To all 'whom it may concern:

Be itknown that I, EDWIN B. LARCHAR, of the city of Baltimore, in the State of Maryland, have invented a new and improved method of making safety-boats or other buoyant vessels of gutta-percha or .gutta-percha mixed with glue and other materials; and I do hereby declare that the following is a full and exact description thereof, reference being had to the accompanying drawings and to the letters of reference marked thereon.

The nature of my invention consists in the employment of gutta percha or gutta percha mixed with common glue and other materials in the proportion of one ounce of glue to every pound of gutta percha both in a heated state, and the molding it into previously prepared forms either so as to complete the desired boat or vessel at one pressure and in one ent-ire piece; or to prepare the air chambers, timbers, supporters, thwarts and other parts separately and then connect them all together simultaneously and at one pressure, so as in that way to complete the boat or vessel finally at once.

To enable others skilled in the art to make and use my invention I will proceed to describe its construction and operation.

The form of the intended boat or of the sections, if it is desired to make it in parts, is first-,- to be made of iron or other metal or suiiiciently hard substance to resist or support the necessary pressure. This form is to be the mold in or upon which the gutt-a percha and its admixture or admiXtures are to be pressed. This mold or model must be so constructed as besides providing for the general form of the boat, lighter, camel, buoy or other float or Vessel, shall contain parts for molding or receiving the molds or forms of buoyant chambers, keel, keelso-n,

gunwales both in and outside; and for brace pieces for the mullocks and gudgeons, and pintles for the rudder if necessary; also for supporters for the thwarts and for the thwarts themselves if required to be cast with the other parts, and also for supporting ring-bolts and a rope padded or other braces or fender on the outside of the boat or vessel, or for any contrivance for attaching the painter, stern sheets, or other ropes or fastenings; or for supporting or strengthening any other parts that may require either stay pieces, air chambers, cutwaters,

stern post, rib, pieces or supporters.

l/Vhere the mold or form has been made the gutta percha` with an ounce of common glue the latter first dissolved in hot water for each pound of the former, is to be reduced or brought by heat to a plastic state suitable to the Acharacter of the work and the intended pressure. Then it is to be rolled into sheets adapted to the size of the boat lmaking an allowance for the eXpansibility of the material. For this purpose the thickness of the sheets is to be in the proportion of four to one of the ultimate thickness when the pressure is finished.

The vessel may be provided with air chambers so as to form hollow gunwales, timbers, keel, keelson, knees, stern posts, cutwater, brace-pieces, and other supporters; or they may be so constructed as to have all those parts filled with solid cork or other light solid body. Those hollow portions may be so arranged as to be made in parts and fitted on to the others; that is to say, the under parts or portions of the buoyant chambers, brace pieces or other supporters may be molded in t-he cavities or suitable places made for the purpose in the general mold of the vessel; and then the upper parts after having been'se'parately prepared in other molds of corresponding or suitable forms, may be cemented and pressed on to those under parts, so as to complete the required cylinders, air chambers, braces, fenders, supporters, or other portions.

-If cork or other light solid body is used to be laid in the beds of the molds for making the cylinders solid whether for gunwales, keel, keelson, dagger-knees, or buoyant chambers, supporters or other parts; then the gutta percha may be applied to the general mold, and the whole boat with all its buoyant and supporting parts including even the thwarts if necessary, may be made at one pressure of the hydraulic or other power. The thwarts may be made of the same material if necessary and hollow, with supporters in the center of light wood at the option of the maker or parties to use the vessel in which latter case of course they must be made separately.

In the preceding method as regards the use of the solid cork or .other light solid material whose specific gravity is not greater than of the gutta percha and admiX- tures, it would aid the buoyancy and strengthen the vessel.

The admixture of `the glue may be vabights or loops at each end with an iron cringle turned in, serve to connect the painter or other ropes at either end of the boat. A light wood sheathing or platform may also be laid on the bottom to stand or work upon.

The gunwales of the boat should be so formed as to gradually widen to the center of the boat; the width being amidships twelve inches, and decreasing properly to veach prow. The object of this width of gunwale is to keep the vessel from careenor air chambers, or bulk heads.

ing too much. If the buoyancy in the whole construction should prove too great, an iron keelson made to suit the form of-the inner portion of the vessel so as to be put on or off at pleasure would remedy that objection. The boat may also have air tight lockers or bulkheads at each end or prow so as to prevent pitching.

A A in the accompanying drawing represents the general form of a safety boat in reference to that particular kind of vessel; B, B, the air vessels or braces or supporters; C, C, the gunwale one foot in width at the center, and diminishing as it approaches the prows; D' D, supporters for the thwarts.

The keel is solid generally. The keelson may be either solid or hollow, and the forms vof the air vessels may be varied either like knees, cross or transverse pieces, supporters, They may likewise be solid or hollow as the size or kind of boat or buoy may require them to be.

The operation of making the boat is by means of the two molds such as shown by the drawings, similar to those now represented. One is a male'mold as shown by Fig. l, in the additional drawing X and the other a female mold as shown by Fig. 2. The force to be applied to produce the form by pressure may be hydraulic steam or other power.

The male mold is made entire or in one connection. The female mold must be divided from stem to stem in the center so as to make vertically two equal parts as seen Figs. Nos. 2 and 4. These equal parts are to be arranged with clamps screws and nuts a a in Figs. Nos. 2 and 4t and 3, to hold them together while under pressure and allow them to be separated when the boat has been pressed so that it may be readily removed.

The sheets of gutta percha prepared as heretofore described in my application are to be laid in the female mold, 2, and then when it is intended to make the boat with solid ribs, brace pieces, keel, keelson, or other parts all of the same material the upper or male mold or form 1 is put on and pressed down with the necessary power. When it is desired to have the ribs, keel, keelson or other parts hollow so as to act as air chambers then the forms of the air chambers, keelson or other parts must be previously and separately prepared and then 'put on the respective and appropriate places while the sheets of gutta percha in the female mold are in a warm state. An air chamber in the form of a rib is shown by Fig. 7. This rib consists of two pieces. One piece is the part showing the form of the cavity Fig. 7 and No. 8. The other is a flat strip of gutta percha made to fit upon and over the part which is to lie upon the sheets in the female mold so as to prevent any portion of those sheets from rising up while under pressure into the cavities of the hollow ribs or air chambers.

Vhen the chambers are not prepared that is to say when hollow ribs or other parts are not required, the sheets of gutta percha are to be laid in the female mold and the male mold pressed down with sufficient force so as to make the forms of ribs, keel, keelson, and other embossed or raised parts entirely solid. These solid parts will be necessarily produced by the rising of the gutta percha into the different cavities while the pressure is applied to the other portions of the sheets. In like manner the hollow parts below or at the sides or ends of the surface of the female form such as the keel, gunwales, cut water and other like parts will receive from the force of such pressure t-he necessary quantity of the gutta percha and become solid portions of the boat.

The female mold is to be securely laid upon a face level to receive the male mold after the sheets of preparedV gutta percha are laid in the former. The male mold may be supported by fall and tackle or by any other common mechanical contrivance directly over the female mold so as to be turned with its cavities down and let into the female mold to receive the pressure.

To make the air chambers which must be prepared separate fromthe main sheets of gutta percha or body of the boat the necessary quantity of the material must be put carefully into a special female mold made of the form required on or suited to the kind of air chamber whether as a rib, gunwale or other such part and then pressed down with a corresponding male mold which shall be of a size so much smaller than the female mold as will be supplied or filled up by the thickness of the parts of the air or hollow chamber, Then the cavity so formed is trimmed and made even, a strip of gutta percha previously made of an equal thick ness with the sides or curve or other portions of the air chamber are of a size to cover the open part of the hollow chamber is to be put upon that open part and then the edges of the air chambers are made to adhere to that strip by running over or searing them with a hot iron. They are then when the sheets of gutta percha are ready in the female mold carefully laid or put upon them in their respective and designed places and as the male mold descends mate into the corresponding openings which it contains and which that male mold sufficiently presses the flat or bottom strip of gutta percha which had closed the air chamber to keep it from collapsing upon the sheets of warm gutta percha which is to form the general outline `or body of the boat, it unites the air chambers and other hollow parts to the main body of the boat and makes it entire firm and complete.

Although this description of making air chambers applied to all such parts of the boat as are cavities it has been found upon experience to be better to make the keel or keelson when they are intended to be hollowA or nearly so, a little stronger by inserting a piece of cork cut into the form of a semicircle and about half the size of the cavity of the keel or keelson and setting the same diagonally in the hollow of the keel or keelson to prevent it from falling in from the sides.

It is not essentially necessary that in order to make the air chambers a separate mold should be made for every or each such chamber as the hollow places in the male mold 1, and that mold itself can be used to make separate air chambers by fitting corresponding parts to press upon, and air chambers when taken out of such molds even in a body can after having strips of gut-ta percha to suit, and the edges of those air chambers seared or heated with a hot iron so as to adhere to those slips be used to be pressed in upon the sheets a body of the boat in the female mold 2 to constitute one compact and entire Vessel. The pressing of the male into the female mold will generally raise portions of the gutta percha above the gunwales. These and other places must be trimmed 0E.

The principle of making gutta percha boats or vessels either with solid or hollow ribs or other parts and at one pressure may be applied to any other shape or model that may be required. The knees, timbers, thwarts, or other pieces or parts may be fashioned to suit the purposes of the intended boat or the taste of the builder.

The invention consists in making a gutta percha boat mixed with glue, either by pressing separately made air vessels upon the body of boat so as to produce a buoyant vessel at one pressure or to make such a boat with solid supporters, knees and other parts all at one time and in one pressure.

In the annexed drawings in duplicate, No. 1 represents the male mold exhibited with the under part turned up; No. 2, the female mold secured or clamped together shown in a side; a a are the screws and nuts; No. 3, sectional or side View of the boat in the female mold as seen when one of the two equal parts or sides of that mold has been unclamped and removed; No. t, female mold seen from above soas to show the interior and division in two equal parts lengthwise; a a are the screws and nuts; No. 5, sectional or side view of the male mold; No. 6, end of the boat in the female mold; No. 7, air chamber with the under part or slip off; No. S, under part or slip of the air chamber to be attached to the other portion of the chamber No. 7 by searing the edges of the latter with a hot iron before the whole is pressed in its place in the boat; No. 9, an end view of an air chamber complete; b at the bottom of this show the slip No. 8 attached.

I disclaim any particular form of boat and all right of invention to air chambers or bulk heads or any cylindrical or other supporters or gunwales; or to the mere making of gutta percha vessels.

Vhat I do claim and desire to secure by Letters Patent is:

The method of making a safety boat or other vessel of gutta percha or gutta percha mixed with glue, so that the air chambers or other parts if separately formed, may, together with the boat body be united and completed at one pressure; or that if the braces, knees, thwarts, supporters, or other accessories to the boat proper, are solid the whole with the inner and outer forms may be all made or completed together at one time and at one pressure substantially in the manner as herein described.

July 5, 1854.

EDWIN B. LARCI-IAR.

Vitnesses:

L. MQBENNETT, WVM. H. I-IAYWARD. 

